Abstract: An image processing device includes: a setting unit configured to set, as reference straight lines, four straight lines which express sense of perspective in a background image and which pass through four sides constituting a rectangular area in the background image, from among a plurality of straight lines included in the background image; a calculating unit configured to calculate a virtual area in a virtual three-dimensional space, the virtual area corresponding to a rectangular display area which has the four reference lines as four sides; and a display control unit configured to display a superimposition image in which the background image and a two-dimensional original image are superimposed, on a display unit, the two-dimensional original image being formed by projecting a three-dimensional original image which is formed by placing an original image in the virtual area, onto a two-dimensional space visually confirmed from a predetermined viewpoint position.

Abstract: An image processing device includes: a setting unit configured to set, as reference straight lines, four straight lines which express sense of perspective in a background image and which pass through four sides constituting a rectangular area in the background image, from among a plurality of straight lines included in the background image; a calculating unit configured to calculate a virtual area in a virtual three-dimensional space, the virtual area corresponding to a rectangular display area which has the four reference lines as four sides; and a display control unit configured to display a superimposition image in which the background image and a two-dimensional original image are superimposed, on a display unit, the two-dimensional original image being formed by projecting a three-dimensional original image which is formed by placing an original image in the virtual area, onto a two-dimensional space visually confirmed from a predetermined viewpoint position.